A git worktree per automation keeps the scheduled bots out of your working directory

A mutex was the first fix, and it worked on the problem it was built for: two automations could no longer run at the same time ^[6]. The question it asks is whether another automation is running, never whether a person is using the folder right now ^[6]. "Detection cannot reliably answer that question. Separation makes it unnecessary," he wrote ^[7].

`git worktree add ~/projects/my-repo-automation feature/pr-comment-fix` gives you a second directory attached to the same repository on its own branch, with no clone and no copy ^[8]. The command needs git 2.5 or newer ^[10]. He calls the add close to instant even on a large repo, and attributes that to the shared `.git` object store ^[8]. The saving is on objects. If the slow part of standing up your repo is materialising a large working tree, the add costs what that checkout costs, once per run.

Two of the ten workflows poll every five minutes ^[14][17]. That is 288 runs a day for each of them ^[18], and each run creates a worktree at step 2 and deletes it at step 5 ^[12]. Step 3 runs the build inside the fresh directory ^[14]. Anything the build needs that git is not tracking has to get there first, and the post does not say how the starter kit handles that; the workflow snippets are described as simplified sketches, with runnable versions later in the post ^[21].

The ticket workflow queries tickets updated in the last two hours, because a query for anything ever assigned to you re-triggers on old work forever ^[17]. At a five-minute cadence, one ticket sits inside that two-hour window for as many as 24 consecutive polls ^[19]. The comment workflow handles the same exposure with state, marking each comment processed once it has acted on it ^[20].

The figure he says surprised him is the split: roughly 70 percent of review comments resolve with no input from him, and the other 30 percent are the ones he actually needs to think about ^[16]. He wrote that sorting comments into those two piles was worth more than the fixes ^[16]. That split was measured on PRs he authored, which is also the only set the bot fires on ^[14]. For it to transfer, your reviewers have to write comments that partition the same way.

Step 5 is the one he says he never bends ^[22]. "Automation does the assembly. I keep the judgment," he wrote ^[13].